The following vmcore was manually induced ([sysrq-d]) from a freshly
booted hugemem kernel on a system with 64 GiB of memory:

    -rw-r--r-- 1 krader krader 68719480832 2007-03-09 12:18:44 /vmware/vmcore

Running crash on it

    crash -d255 System.map-2.4.21-47.0.1.ELhugemem /vmware/vmcore \
    ./usr/lib/debug/boot/vmlinux-2.4.21-47.ELhugemem.debug

Fails with
 
 

 
crash: ./usr/lib/debug/boot/vmlinux-2.4.21-47.ELhugemem.debug: no text and data contents

crash: the use of a System.map file requires that the accompanying namelist
argument is a kernel file built with the -g CFLAG.  The namelist argument
supplied in this case is a debuginfo file, which must be accompanied by the
kernel file from which it was derived.
 

As the error message above states, "the namelist argument supplied
is a debuginfo file, which must be accompanied by the kernel file from
which it was derived".

 crash -d255 System.map-2.4.21-47.0.1.ELhugemem /vmware/vmcore \
    ./usr/lib/debug/boot/vmlinux-2.4.21-47.ELhugemem.debug

Get rid of the System.map file, and then go find and put the
/boot/vmlinux-2.4.21-47.ELhugemem file on the comand line.

RHEL3 had that inane "split-vmlinux-and-vmlinux.debug"
scheme, as if it were a user application.  Fortunately sanity
took over in RHEL4, and they decided to just keep the
single -g built vmlinux file as a single entity in the kernel
debuginfo package.

A System.map file argument is *never* required unless the
vmlinux file does not match the vmcore file.

Dave